Image MIME Reference
GIF
Graphics Interchange Format
image/gif
VS
JPEG 2000 Image (HEIF Container)
image/hej2k
HEJ2K
A complete technical comparison of Graphics Interchange Format and JPEG 2000 Image (HEIF Container) — covering compression, feature support, browser compatibility, magic bytes, and when to choose each format.
GIF wins on browser support
Feature Support
| Feature | GIF | HEJ2K |
|---|---|---|
| Transparency (Alpha) | Yes | Yes |
| Animation Support | Yes | ✕ No |
| Progressive Loading | Yes | Yes |
| HDR Support | ✕ No | Yes |
| EXIF Metadata | ✕ No | Yes |
| ICC Color Profile | Yes | Yes |
Graphics Interchange Format
image/gif
Extension
.gif
Container
GIF
Compression
Lossless (LZW)
Algorithm
LZW (Lempel-Ziv-Welch)
Color Depth
1-bit, 4-bit, 8-bit (Indexed)
Developed by
CompuServe
Released
1987
Magic Bytes
47 49 46 38 39 61
JPEG 2000 Image (HEIF Container)
image/hej2k
Extension
.hej2
Container
HEIF / ISOBMFF (ISO/IEC 15444-16)
Compression
Lossy / Lossless
Algorithm
JPEG 2000HTJ2K
Color Depth
8-bit, 10-bit, 12-bit, 16-bit
Developed by
ISO/IEC JTC 1 / ITU-T
Released
2019
Magic Bytes
XX XX XX XX 66 74 79 70 6A 32 6B 69
Browser Support Comparison
| Browser | GIF | HEJ2K |
|---|---|---|
Chrome
|
✓ All
|
✕ |
Firefox
|
✓ All
|
✕ |
Safari
|
✓ All
|
✕ |
Edge
|
✓ All
|
✕ |
IE (Legacy)
|
✓
|
✕ |
GIF
GIF Strengths
- Universal support across all web browsers, operating systems, and messaging apps
- Supports basic frame-by-frame animation out of the box
- Lossless compression is highly effective for simple, flat-color graphics like logos or pixel art
Limitations
- Limited to 256 colors per frame, resulting in poor quality for complex gradients and photographs
- Animations produce massive file sizes compared to modern formats like MP4, WebP, or AVIF
- 1-bit transparency limits edge blending on non-uniform backgrounds
HEJ2K
HEJ2K Strengths
- Brings the extensive capabilities of the HEIF container (like EXIF/XMP, thumbnails, and depth maps) to JPEG 2000
- Supports mathematically lossless compression via wavelet transformation
- High scalability and progressive decoding out of the box
Limitations
- Extremely limited software support outside of niche industries
- Zero native compatibility with web browsers
- High computational complexity compared to simpler formats like JPEG or PNG
When to choose which format
GIF
Use GIF when…
- Web Animations
- Memes
- Simple Graphics
- Logos with flat colors
HEJ2K
Use HEJ2K when…
- Medical Imaging
- Geospatial Data
- Scientific Archiving